1. Technical
The present disclosure relates generally to cooling apparatuses and, more particularly, to a split-type low-temperature cooling apparatus.
2. Description of the Related Art
A superconducting quantum interference device (hereinafter referred to as “SQUID”) sensor used to measure biomagnetism operates at extremely low temperature of absolute temperature 4K. The SQUID sensor has measurement sensitivity of several to tens of fT/√Hz. Accordingly, a SQUID system for measuring biomagnetism requires a low-temperature coolant storage container capable of storing an ultralow-temperature coolant. The low-temperature coolant storage container must be formed of a non-magnetic material to stably operate a SQUID sensor without distortion of a magnetic field generated from a living body. Moreover, liquid helium used as a coolant of the SQUID sensor is high-priced. Accordingly, since the supply of a coolant is limited, an evaporation rate of the coolant needs to be minimized.